This image shows the path the Mars Exploration Rover Spirit has traveled since it landed 53 martian days, or sols, ago. "Laguna Hollow," the shallow depression where Spirit dug a trench, can be seen to the right of center. Spirit stayed at "Laguna Hollow" for 3 sols, investigating the fine-grained soil contained there and the trench it dug with one of its wheels. The rover is headed northeast toward a large crater nicknamed "Bonneville." This panoramic camera image was taken from the rover's new location, a region dubbed "Middle Ground" located 98 meters (322 feet) away from "Bonneville."

This image shows the Mars Exploration Rover Spirit's view of the rocky terrain that lies between it and its intended target, the large crater dubbed "Bonneville." The landscape here is roughly two times as bumpy and more difficult to traverse than that crossed so far. Spirit has currently stopped to examine the soil and rocks at a region nicknamed "Middle Ground." The rover is 98 meters (322 feet) away from "Bonneville" and facing northeast. The large rock called "Humphries" can be seen in the lower right corner. The image was taken on the 53rd martian day, or sol, of Spirit's mission by the rover's panoramic camera.

This map shows the Mars Exploration Rover Spirit's travels since arriving on the red planet Jan. 3, 2004 PST. Spirit is on its way to a large crater nicknamed "Bonneville." On the 52nd day, or sol, of its mission (Feb. 25, 2004), it stopped off at a region nicknamed "Middle Ground" to investigate rocks and soil. The rover is facing northeast and is 98 meters (322 feet) away from the rim of "Bonneville." Data within the yellow box represent a digital map made of images taken by the rover's panoramic and navigation cameras. Data outside this box are a composite of images from the rover's descent image motion estimation system camera and NASA's orbiter Mars Global Surveyor.

This approximate true-color image taken by the Mars Exploration Rover Spirit's panoramic camera shows the windblown waves of soil that characterize the rocky surface of Gusev Crater, Mars. Scientists were puzzled about whether these geologic features were "ripples" or "dunes." Ripples are shaped by gentle winds that deposit coarse grains on the tops or crests of the waves. Dunes are carved by faster winds and contain a more uniform distribution of material. Images taken of these features by the rover's microscopic imager on the 41st martian sol, or day, of the rover's mission revealed their identity to be ripples. This information helps scientists better understand the winds that shape the landscape of Mars. This image was taken early in Spirit's mission.

This false-color image from the Mars Exploration Rover Spirit's panoramic camera shows peak-like formations on the martian terrain at Gusev Crater. Scientists have been analyzing these formations, which have coarse particles accumulating on their tops, or crests. This characteristic classifies them as ripples instead of dunes, which have a more uniform distribution of particle sizes. Scientists are looking further into such formations, which can give insight to the wind direction and velocity on Mars, as well as the material that is being moved by the wind. This image was taken on the 40th martian day, or sol, of Spirit's mission.

This diagram illustrates how windblown sediments travel. There are three basic types of particles that undergo different motions depending on their size. These particles are dust, sand and coarse sand, and their sizes approximate flour, sugar, and ball bearings, respectively. Sand particles move along the "saltation" path, hitting the surface downwind. When the sand hits the surface, it sends dust into the atmosphere and gives coarse sand a little shove. Mars Exploration Rover scientists are studying the distribution of material on the surface of Mars to better understand how winds shape the landscape.

This microscopic image taken by the Mars Exploration Rover Spirit shows the troughs between the waves of windblown soil that characterize the surface of Gusev Crater, Mars. The fine-grained soil in the troughs, combined with the coarse grains observed in a similar microscopic image taken of the waves' crests, indicate that the waves are geologic features known as ripples, and not dunes. Dunes contain a more uniform distribution of material. This information helps scientists better understand the winds that shape the landscape of Mars. The image was taken on the 41st martian day, or sol, of the rover's mission by its microscopic imager. The observed area is 3 centimeters (1.2 inches) across.

This microscopic image taken by the Mars Exploration Rover Spirit shows the tops or crests of the waves of windblown soil that characterize the surface of Gusev Crater, Mars. The coarse grains on the crests, combined with the finer grains observed in a similar microscopic image taken of the waves' troughs, indicate that the waves are geologic features known as ripples, and not dunes. Dunes contain a more uniform distribution of material. This information helps scientists better understand the winds that shape the landscape of Mars. The image was taken on the 41st martian day, or sol, of the rover's mission by its microscopic imager. The observed area is 3 centimeters (1.2 inches) across.